Abstract: A filter device (130) is formed between an input end (T1) and an output end (T2), and is configured to attenuate a radio frequency signal in a specific frequency band. The filter device (130) includes a dielectric substrate (140) having a multilayer structure, ground electrodes (GND1 and GND2) formed in the dielectric substrate (140), a first coupling line (132) electrically connected to the input end (T1), a second coupling line (134) electrically connected to the output end (T2), and a stub (133) connected to the first coupling line (132) and the second coupling line (134). The first coupling line (132) and the second coupling line (134) are formed in layers different from layers of the ground electrodes (GND1 and GND2). The first coupling line (132) and the second coupling line (134) are disposed in different layers so as to face each other.

Abstract: An antenna module (100) includes a dielectric substrate (125), antenna groups (123A, 123B) including a plurality of antenna elements (121), RFICs (110A, 110B) configured to supply radio-frequency power to the antenna groups (123A, 123B), a divider (140) configured to divide a radio-frequency signal between the RFICs (110A, 110B), and a ground electrode (GND2). The RFICs (110A, 110B) are mounted at a mounting surface (126) of the dielectric substrate (125). The divider (140) is provided closer to the mounting surface (126) than to the layer in which the antenna groups (123A, 123B) are provided. The divider (140) includes a first path having lower impedance and a second path having higher impedance. When viewed in plan view in a normal-line direction with respect to the mounting surface (126), a cavity (300) is formed at a portion of the ground electrode (GND2), the portion facing the second path.

Abstract: A filter device (130) is formed between an input end (T1) and an output end (T2), and is configured to attenuate a radio frequency signal in a specific frequency band. The filter device (130) includes a dielectric substrate (140) having a multilayer structure, ground electrodes (GND1 and GND2) formed in the dielectric substrate (140), a first coupling line (132) electrically connected to the input end (T1), a second coupling line (134) electrically connected to the output end (T2), and a stub (133) connected to the first coupling line (132) and the second coupling line (134). The first coupling line (132) and the second coupling line (134) are formed in layers different from layers of the ground electrodes (GND1 and GND2). The first coupling line (132) and the second coupling line (134) are disposed in different layers so as to face each other.

Abstract: The present disclosure includes: an RFIC (110A) and an RFIC (110B) that are configured to respectively supply radio-frequency power to a first antenna group and a second antenna group; and a divider that divides a reference frequency signal input thereto and outputs the resulting first radio-frequency signals to the RFIC (110A) and the RFIC (110B). The divider is a Wilkinson-type first divider that is formed of a circuit system of a second impedance that is lower than a first impedance that is an impedance of signal transmission system into which the divider is inserted.

Abstract: The present disclosure includes: an RFIC (110A) and an RFIC (110B) that are configured to respectively supply radio-frequency power to a first antenna group and a second antenna group; and a divider that divides a reference frequency signal input thereto and outputs the resulting first radio-frequency signals to the RFIC (110A) and the RFIC (110B). The divider is a Wilkinson-type first divider that is formed of a circuit system of a second impedance that is lower than a first impedance that is an impedance of signal transmission system into which the divider is inserted.

Abstract: An antenna module (100) includes a dielectric substrate (125), antenna groups (123A, 123B) including a plurality of antenna elements (121), RFICs (110A, 110B) configured to supply radio-frequency power to the antenna groups (123A, 123B), a divider (140) configured to divide a radio-frequency signal between the RFICs (110A, 110B), and a ground electrode (GND2). The RFICs (110A, 110B) are mounted at a mounting surface (126) of the dielectric substrate (125). The divider (140) is provided closer to the mounting surface (126) than to the layer in which the antenna groups (123A, 123B) are provided. The divider (140) includes a first path having lower impedance and a second path having higher impedance. When viewed in plan view in a normal-line direction with respect to the mounting surface (126), a cavity (300) is formed at a portion of the ground electrode (GND2), the portion facing the second path.

Abstract: The present disclosure includes a first circuit that is connected between a power feed port and an antenna port, and a second circuit that is connected between the power feed port and the ground or between the antenna port and the ground. The first circuit is a circuit in which for example a first variable capacitance element is connected in series with a first inductor, and the second circuit is a circuit in which for example a second variable capacitance element is connected in parallel with a second inductor. A switch performs switching at least between a first state in which a second end of the second circuit is connected to a first end of the first circuit and a second state in which the second end of the second circuit is connected to a second end of the first circuit.

Abstract: There are provided an antenna, an antenna tuner configured to adjust frequency characteristics of the antenna, and a control circuit configured to change frequency characteristics of the antenna tuner in a boundary time set for a unit of time of communication. For example, after matching indicators based on VSWRs and received signal strength indicators based on RSSIs have been acquired in a plurality of times of communication space time, the antenna tuner is put into an optimum mode. This suppresses the decrease in communication throughput caused by the adjustment of the antenna tuner and suppresses the interruption of communication at the time of adjustment of the antenna tuner.

Abstract: A variable phase shift circuit has a phase shifter including a first port and a second port; a through path including a first port and a second port; a first switch including a first common port and configured to select the first port of the phase shifter or the first port of the through path and to connect the first port or the first port to the first common port; and a second switch including a second common port and configured to select the second port of the phase shifter or the second port of the through path and to connect the second port or the second port to the second common port. Phase shift amounts between the first common port and the second common port are switched in accordance with selections made by the first switch and the second switch.

Abstract: Provided is a method for setting a communication channel for a base station employing carrier aggregation, which enables simultaneous use of radio waves at a plurality of frequency bands of different frequencies or a base station apparatus for setting a communication channel in accordance with carrier aggregation, which enables simultaneous transmission and reception at a plurality of frequency bands of different frequencies. At least one of a downlink frequency channel in a first frequency band and a downlink frequency channel in a second frequency band is set such that a frequency range of harmonics of an uplink frequency range in the first frequency band does not overlap a downlink frequency range in the second frequency band, the first frequency band and the second frequency band being included in the plurality of frequency bands for use in carrier aggregation.

Abstract: In an antenna device including a high-band antenna element and a low-band antenna element that are connected to a common feed point and feeding electric power using one feed point, influence by unnecessary resonance of the low-band antenna element in a high band is suppressed. The antenna device includes a high-band antenna element and a low-band antenna element that are connected to a common feed point, an antenna-shortening inductor that is connected to between the low-band antenna element and the feed point, and a capacitor that is connected to the antenna-shortening inductor in parallel.

Abstract: A front end circuit includes a circulator having a first port into which a transmission signal is input, a second port into/from which a transmission/reception signal is input/output, and a third port from which a reception signal is output. The impedance of the second port of the circulator is set to a value different from the impedance value of the first port and the third port. With his configuration, the narrowing of a frequency band and the increase in loss, which occur when an impedance matching circuit is additionally provided, are prevented.

Abstract: A variable phase shift circuit has a phase shifter including a first port and a second port; a through path including a first port and a second port; a first switch including a first common port and configured to select the first port of the phase shifter or the first port of the through path and to connect the first port or the first port to the first common port; and a second switch including a second common port and configured to select the second port of the phase shifter or the second port of the through path and to connect the second port or the second port to the second common port. Phase shift amounts between the first common port and the second common port are switched in accordance with selections made by the first switch and the second switch.

Abstract: There are provided an antenna, an antenna tuner configured to adjust frequency characteristics of the antenna, and a control circuit configured to change frequency characteristics of the antenna tuner in a boundary time set for a unit of time of communication. For example, after matching indicators based on VSWRs and received signal strength indicators based on RSSIs have been acquired in a plurality of times of communication space time, the antenna tuner is put into an optimum mode. This suppresses the decrease in communication throughput caused by the adjustment of the antenna tuner and suppresses the interruption of communication at the time of adjustment of the antenna tuner.

Abstract: The present disclosure includes a first circuit that is connected between a power feed port and an antenna port, and a second circuit that is connected between the power feed port and the ground or between the antenna port and the ground. The first circuit is a circuit in which for example a first variable capacitance element is connected in series with a first inductor, and the second circuit is a circuit in which for example a second variable capacitance element is connected in parallel with a second inductor. A switch performs switching at least between a first state in which a second end of the second circuit is connected to a first end of the first circuit and a second state in which the second end of the second circuit is connected to a second end of the first circuit.

Abstract: A front-end circuit includes a band switching unit (20) that is directly or indirectly connected to an antenna (10) and that switches connection to a frequency band used in transmission and reception, among multiple frequency bands, multiple demultiplexers (31 to 34) that perform demultiplexing into transmission signals and reception signals in the respective frequency bands, and antenna matching circuits (41 to 44). One of the antenna matching circuits (41 to 44) is disposed between at least one demultiplexer, among the multiple demultiplexers (31 to 34), and the band switching unit (20). For example, the antenna matching circuits (41 to 44) include reactance elements (L1, L2, C32, C42) that are connected in series to circuits connecting the band switching unit (20) to the demultiplexers (31 to 34) and reactance elements (C1, C2, C31, C41) that are connected in parallel thereto, respectively.

Abstract: Provided is a method for setting a communication channel for a base station employing carrier aggregation, which enables simultaneous use of radio waves at a plurality of frequency bands of different frequencies or a base station apparatus for setting a communication channel in accordance with carrier aggregation, which enables simultaneous transmission and reception at a plurality of frequency bands of different frequencies. At least one of a downlink frequency channel in a first frequency band and a downlink frequency channel in a second frequency band is set such that a frequency range of harmonics of an uplink frequency range in the first frequency band does not overlap a downlink frequency range in the second frequency band, the first frequency band and the second frequency band being included in the plurality of frequency bands for use in carrier aggregation.

Abstract: In an antenna device including a high-band antenna element and a low-band antenna element that are connected to a common feed point and feeding electric power using one feed point, influence by unnecessary resonance of the low-band antenna element in a high band is suppressed. The antenna device includes a high-band antenna element and a low-band antenna element that are connected to a common feed point, an antenna-shortening inductor that is connected to between the low-band antenna element and the feed point, and a capacitor that is connected to the antenna-shortening inductor in parallel.

Abstract: A front end circuit includes a circulator having a first port into which a transmission signal is input, a second port into/from which a transmission/reception signal is input/output, and a third port from which a reception signal is output. The impedance of the second port of the circulator is set to a value different from the impedance value of the first port and the third port. With his configuration, the narrowing of a frequency band and the increase in loss, which occur when an impedance matching circuit is additionally provided, are prevented.

Abstract: An elastic wave filter device has a center frequency of a reception frequency band. A plurality of parallel arms are connected to a portion of a series arm on a second signal terminal side of a portion in which a first series-arm resonator is provided. Series-arm resonators among the plurality of series-arm resonators other than the first series-arm resonator include a series-arm resonator having a resonant frequency higher than the resonant frequency of the first series-arm resonator. The resonant frequency of the first series-arm resonator is equal to the reception frequency band.